Image forming apparatuses form an image on a printing sheet by emitting light to a charged photosensitive drum, change a potential of portions exposed to the light to form an electrostatic latent image on the photosensitive drum, and transfer a developer image formed with the supply of developer to the electrostatic latent image onto the printing sheet.
In some of such image forming apparatuses, plural LED heads which emits light to plural photosensitive drums and plural process units which includes the photosensitive drums and toner containers are alternately arranged in a direction (see JP-A-H9-160333). In the image forming apparatuses, the LED heads are supported by a rotatable top cover and can get close to and apart from the photosensitive drums.
However, with the above-described configuration, since each LED head is moved along an arc-shaped locus, gaps between the process units should be large so that the LED heads do not interfere with the process units when rotating the top cover, thereby increasing the size of the apparatus.